Evaluation and Management of Glenohumeral Instability With Associated Bone Loss: An Expert Consensus Statement Using the Modified Delphi Technique

Arthroscopic Bone Block Stabilization for Anterior Shoulder Instability with Subcritical Glenohumeral Bone Loss

PURPOSE OF REVIEW

The management options for anterior shoulder instability with minimal bone loss or with critical bone loss are well established. However, there is less clear evidence to guide management for patients with subcritical bone loss, the spectrum of pathology where soft tissue repair alone is prone to higher rates of failures. In this range of bone loss, likely around 13.5% to 20%, the goal of surgery is to restore function and stability while limiting morbidity. As with many procedures in the shoulder, this decision should be tailored to patient anatomy, functional goals, and risk factors. This article provides a review of our current understanding of subcritical bone loss and treatment strategies as well as innovations in management.

RECENT FINDINGS

While surgeons have largely understood that restoration of anatomy is important to optimize outcomes after stabilization surgery, there is increasing evidence that reconstructing bony anatomy and addressing both osseous and soft tissue structures yields better results than either alone. Even in the setting of subcritical bone loss, there is likely a benefit to combined osseous augmentation with soft tissue management. Additionally, there is new evidence to support management of even on-track humeral lesions when the distance to dislocation is sufficiently small, particularly for athletes. Surgeons must balance bony and soft tissue restoration to achieve optimal outcomes for anterior instability with subcritical bone loss. There are still significant limitations in the literature and several emerging techniques for management will require further study to prove their long-term efficacy. Beyond surgery, there should be a focus on a collaborative treatment strategy with the surgeon, patient, and therapists to achieve high-level function and minimize recurrence.

Clinical Equipoise in the Management of Patients With Femoroacetabular Impingement Syndrome and Concomitant Tönnis Grade 2 Hip Osteoarthritis or Greater: An International Expert-Panel Delphi Study

PURPOSE

To gather global-expert opinion on the management of patients with femoroacetabular impingement syndrome (FAIS) and Tönnis grade 2 hip osteoarthritis (OA) or greater.

METHODS

An internet-based modified Delphi methodology was used via an online platform (Online Surveys) using the CREDES (Conducting and Reporting Delphi Studies) guidelines. The expert panel comprised 27 members from 18 countries: 21 orthopaedic surgeons (78%), 5 physiotherapists (18%), and 1 dual orthopaedic surgeon-sport and exercise medicine physician (4%). Comments and suggestions were collected during each round, and amendments were performed for the subsequent round. Between each pair of rounds, the steering panel provided the experts with a summary of results and amendments. Consensus was set a priori as minimum agreement of 80%.

RESULTS

Complete participation (100%) was achieved in all 4 rounds. A final list of 10 consensus statements was formulated. The experts agreed that there is no single superior management strategy for FAIS with Tönnis grade 2 OA and that Tönnis grade 3 OA and the presence of bilateral cartilage defects (acetabular and femoral) is a contraindication for hip preservation surgery. Nonoperative management should include activity modification and physiotherapy with hip-specific strengthening, lumbo-pelvic mobility training, and core strengthening. There was no consensus on the need for 3-dimensional imaging for initial quantification of joint degeneration.

CONCLUSIONS

There is clinical equipoise in terms of the best management strategy for patients with FAIS and Tönnis grade 2 OA, and therefore, there is an urgent need to perform a randomized controlled trial for this cohort of patients to ascertian the best management strategy.

LEVEL OF EVIDENCE

Level V, expert opinion.

Editorial Commentary: Two-Thirds Glenoid Height Technique Used to Generate a "Perfect Circle" Improves Reliability in Measuring Shoulder Glenoid Bone Loss

When determining surgical options for shoulder stabilization, patient age, lifestyle, and sport activities help inform which procedure to select. Additionally, there is a need for solidifying the accuracy and effectiveness of measuring glenoid bone loss, which can be the critical factor in choosing a soft tissue or bony augmentation procedure. Makovicka et al. found that using two-thirds of the glenoid height to generate a perfect-circle, rather than a "best-fit" circle improved reliability of MRI-based bone loss measurement. Two-thirds height technique employs a more objective measure of glenoid height, producing a perfect circle used to subsequently estimate glenoid bone loss, which is consistently reproducible, and can be performed in most clinical settings. This was supported by the improved intra-class correlation coefficient from the two-thirds height perfect circle over the "best-fit" circle measurement observed in this study.

Surgical Intervention Following a First Traumatic Anterior Shoulder Dislocation Is Worthy of Consideration

Up to 60% of patients experience recurrence after a first traumatic anterior shoulder dislocation (FTASD), which is often defined as having experienced either dislocation or subluxation. Thus surgical intervention after FTASD is worthy of consideration and is guided by the number of patients who need to receive surgical intervention to prevent 1 redislocation (i.e., number needed to treat), (subjective) health benefit, complication risk, and costs. Operative intervention through arthroscopic stabilization can be successful in reducing recurrence risk in FTASD, as has been shown in multiple randomized controlled trials. Nevertheless, there is a large "gray area" for the indication of arthroscopic stabilization, and it is therefore heavily debated which patients should receive operative treatment. Previous trials showed widely varying redislocation rates in both the intervention and control group, meta-analysis shows 2% to 19% after operative and 20% to 75% after nonoperative treatment, and redislocation rates may not correlate with patient-reported outcomes. The literature is quite heterogeneous, and a major confounder is time to follow-up. Furthermore, there is insufficient standardization of reporting of outcomes and no consensus on definition of risk factors. As a result, surgery is a reasonable intervention for FTASD patients, but in which patients it best prevents redislocation requires additional refinement.

High variability in what is considered important to report following instability surgery: a Delphi study among Dutch shoulder specialists

Background

Standardized reporting leads to high-quality data and can reduce administration time. The aim of this study was to (1) get an insight into the variability of what is considered important to report in the surgical report following shoulder instability surgery and (2) determine which elements should be included in the surgical report following shoulder instability surgery according to Dutch surgeons using a Delphi method.

Methods

Dutch orthopedic shoulder surgeons were included in a panel for a Delphi study consisting of 3 rounds. Importance of the elements was rated on a 9-point Likert scale. High variability was defined as an element that received at least 1 score between 1 and 3 and 1 score between 7 and 9 in round 3. Consensus was defined as ≥80% of the panel giving a score of 7 or more.

Results

Seventeen shoulder specialists completed all 3 rounds and identified a total of 82 elements for the arthroscopic Bankart repair and 60 for the open Latarjet. High variability was observed in 57 (70%) and 52 (87%) of the elements, respectively. After round 3, the panel reached consensus on 27 and 11 elements that should be mentioned in the surgical report following arthroscopic Bankart repair and open Latarjet.

Conclusion

There is high variability in what shoulder specialists regard essential to report. Consensus was reached on 27 and 11 elements to be reported following arthroscopic Bankart repair and open Latarjet, respectively. Future studies on an international scale can further improve data collection and communication between specialists.

Complete Restoration of Native Glenoid Width Improves Glenohumeral Biomechanics After Simulated Latarjet

BACKGROUND

The amount of glenoid width that must be restored with a Latarjet procedure in order to reestablish glenohumeral stability has not been determined.

PURPOSE/HYPOTHESIS

The purpose of this article was to determine the percentage of glenoid width restoration necessary for glenohumeral stability after Latarjet by measuring anterior humeral head translation and force distribution on the coracoid graft. The hypothesis was that at least 100% of glenoid width restoration with Latarjet would be required to maintain glenohumeral stability.

STUDY DESIGN

Controlled laboratory study.

METHODS

Nine cadaveric shoulders were prepared and mounted on an established shoulder simulator. A lesser tuberosity osteotomy (LTO) was performed to allow accurate removal of glenoid bone. Coracoid osteotomy was performed, and the coracoid graft was sized to a depth of 10 mm. Glenoid bone was sequentially removed, and Latarjet was performed using 2 screws to reestablish 110%, 100%, 90%, and 80% of native glenoid width. The graft was passed through a subscapularis muscle split, and the LTO was repaired. A motion tracking system recorded glenohumeral translations, and force distribution was recorded using a TekScan pressure sensor secured to the glenoid face and coracoid graft. Testing conditions included native; LTO; Bankart tear; and 110%, 100%, 90%, and 80% of glenoid width restoration with Latarjet. Glenohumeral translations were recorded while applying an anteroinferior load of 44 N at 90° of humerothoracic abduction and 0° or 45° of glenohumeral external rotation. Force distribution was recorded without an anteroinferior load.

RESULTS

Anterior humeral head translation progressively increased as the proportion of glenoid width restored decreased. A marked increase in anterior humeral head translation was found with 90% versus 100% glenoid width restoration (10.8 ± 3.0 vs 4.1 ± 2.6 mm, respectively; P < .001). Greater glenoid bone loss also led to increased force on the coracoid graft relative to the native glenoid bone after Latarjet. A pronounced increase in force on the coracoid graft was seen with 90% versus 100% glenoid width restoration (P < .001).

CONCLUSION

Anterior humeral head translation and force distribution on the coracoid graft dramatically increased when <100% of the native glenoid width was restored with a Latarjet procedure.

CLINICAL RELEVANCE

If a Latarjet is unable to fully restore the native glenoid width, surgeons should consider alternative graft sources to minimize the risk of recurrent instability or coracoid overload.

Arthroscopic Dynamic Anterior Stabilization Using Either Long Head of the Biceps or Conjoined Tendon Transfer for Anterior Shoulder Instability Results in a Similarly Low Recurrence Rate

PURPOSE

To compare the clinical outcomes of arthroscopic dynamic anterior stabilization (DAS) between transferring the long head of the biceps (DAS-LHB) and the conjoined tendon (DAS-CT) for anterior shoulder instability with <15% glenoid bone loss.

METHODS

From January 2016 to May 2019, a total of 63 patients who underwent DAS for recurrent anterior shoulder dislocation with <15% glenoid bone loss were included, comprising 33 patients in DAS-LHB group and 30 patients in DAS-CT group. Clinical outcomes were assessed preoperatively and at a minimum 3-year follow-up, including patient-reported outcomes, range of motion, and return to sports (RTS). Postoperative recurrent instability (including dislocation, subluxation, and subjective instability with a positive apprehension test), revisions and complications also were recorded.

RESULTS

No significant demographic characteristics difference was detected between the DAS-LHB (26.3 ± 7.9 years) and DAS-CT groups (26.0 ± 6.7 years). At the latest follow-up, there were no significant differences between the 2 groups in functional scores: Oxford Shoulder Instability Score (14.8 ± 2.8 vs 15.2 ± 3.6), Rowe score (95.9 ± 6.5 vs 93.2 ± 10.2), visual analog scale for pain (0.8 ± 1.2 vs 0.7 ± 1.7), and American Shoulder and Elbow Surgeons (95 ± 8.8 vs 95.2 ± 9.1) (all P > .218). No significant difference was detected between groups in the rates of RTS (90.1% vs 86.7%, P = .700) and RTS at previous level (78.7% vs 73.3%, P = .258), respectively. No recurrent dislocation occurred in either group. One patient felt occasional subluxation in the DAS-LHB group, and one was positive for the apprehension test in each group. One patient presented with postoperative shoulder stiffness and underwent a secondary arthroscopic debridement in the DAS-CT group.

CONCLUSIONS

Comparable rates of recurrence, complication, return to sports, and subjective shoulder function were observed between DAS-LHB and DAS-CT groups.

LEVEL OF EVIDENCE

Ⅲ; retrospective comparative therapeutic trial.

Calculating glenoid bone loss based on glenoid height using ipsilateral three-dimensional computed tomography

PURPOSE

To investigate the relationship between glenoid width and other morphologic parameters using three-dimensional (3D) computed tomography (CT) images of native shoulders, and to create a new measurement tool to assess glenoid defects in a Canadian population with established anterior shoulder instability.

METHODS

Forty-three glenoid CT scans were analyzed for patients who underwent contralateral shoulder glenoid reconstruction for anterior shoulder instability between 2012 and 2020. Demographic data were obtained including age, gender and BMI. The subjects were excluded if they had a prior history of ipsilateral shoulder instability, shoulder fractures, or bone tumors. The following glenoid parameters were measured: width (W), height (H), anteroposterior (AP) depth, superior-inferior (SI) depth and version. The shape of the glenoid was also classified into pear, inverted comma or oval.

RESULTS

There were 35 male and 8 females with a mean age of 34.5 ± 12.9 years. The glenoid width was strongly correlated with the height (R² = 0.9) and a regression model equation was obtained: W (mm) = 2.5 + 0.7*H (mm). There was also strong correlation with gender (P < 0.001), glenoid shape (P = 0.030), AP and SI depths (P = 0.006 and P < 0.001, respectively). Male gender was associated with higher measurement values for all parameters. The most common glenoid shapes were the pear (46.5%) and oval morphotypes (39.6%) for the whole study group.

CONCLUSION

The native glenoid width can be estimated based on glenoid height using ipsilateral 3D CT. This may help with preoperative planning and surgical decision-making for patients with anterior shoulder instability and glenoid bone loss.

LEVEL OF EVIDENCE

III.

Glenoid bone loss in anterior shoulder dislocation: a multicentric study to assess the most reliable imaging method

PURPOSE

The aim of this multicentric study was to assess which imaging method has the best inter-reader agreement for glenoid bone loss quantification in anterior shoulder instability. A further aim was to calculate the inter-method agreement comparing bilateral CT with unilateral CT and MR arthrography (MRA) with CT measurements. Finally, calculations were carried out to find the least time-consuming method.

METHOD

A retrospective evaluation was performed by 9 readers (or pairs of readers) on a consecutive series of 110 patients with MRA and bilateral shoulder CT. Each reader was asked to calculate the glenoid bone loss of all patients using the following methods: best fit circle area on both MRA and CT images, maximum transverse glenoid width on MRA and CT, CT PICO technique, ratio of the maximum glenoid width to height on MRA and CT, and length of flattening of the anterior glenoid curvature on MRA and CT. Using Pearson's correlation coefficient (PCC), the following agreement values were calculated: the inter-reader for each method, the inter-method for MRA with CT quantifications and the inter-method for CT best-fit circle area and CT PICO. Statistical analysis was carried out to compare the time employed by the readers for each method.

RESULTS

Inter-reader agreement PCC mean values were the following: 0.70 for MRA and 0.77 for CT using best fit circle diameter, 0.68 for MRA and 0.72 for CT using best fit circle area, 0.75 for CT PICO, 0.64 for MRA and 0.62 for CT anterior straight line and 0.49 for MRA and 0.43 for CT using length-to-width ratio. CT-MRA inter-modality PCC mean values were 0.9 for best fit circle diameter, 0.9 for best fit circle area, 0.62 for anterior straight line and 0.94 for length-to-width methods. PCC mean value comparing unilateral CT with PICO CT methods was 0.8. MRA best fit circle area method was significantly faster than the same method performed on CT (p = 0.031), while no significant difference was seen between CT and MRA for remaining measurements.

CONCLUSIONS

CT PICO is the most reliable imaging method, but both CT and MRA can be reliably used to assess glenoid bone loss. Best fit circle area CT and MRA methods are valuable alternative measurement techniques.

Knotless Arthroscopic Glenoid Labral Stabilization for a 270° Tear With Concurrent Remplissage in the Lateral Decubitus Position

Labral tears resulting in 270° near-circumferential pathology predispose patients to recurrent instability and are technically challenging to repair. Furthermore, when such lesions are associated with Hill-Sachs lesions, recurrent instability risk is significantly increased and can result in substantially lower clinical outcomes. When determining a surgical treatment algorithm for shoulder stabilization, it is important to consider both humeral- and glenoid-sided pathology because subtle defects can have significant influence on recurrence and patient reported outcomes. In this Technical Note and accompanying video, we discuss our surgical technique for knotless arthroscopic stabilization for a 270° labral tear with concurrent remplissage in the setting of recurrent shoulder instability.

Assessing Bone Loss in the Unstable Shoulder: a Scoping Review

PURPOSE OF REVIEW

The aim of this scoping review is to identify and summarize findings published in the literature over the past 5 years related to methods for assessment of bone loss in anterior shoulder instability.

RECENT FINDINGS

Of the 113 clinical studies included in this review, 76 reported a cutoff for glenoid bone loss when determining the patients indicated for one of the many stabilization procedures investigated. Bone loss on the glenoid side was evaluated most commonly with three-dimensional computed tomography (3D CT), and either linear or surface area-based methods were employed with the use of a best-fit circle. When combined with plain CT, the two methods comprise up to 70% of the reported measurement techniques for glenoid bone loss (79 of 113 studies). On the humeral side, Hill-Sachs lesions were assessed more heterogeneously, though plain CT or 3D CT remained the methods of choice in the majority of studies (43 of 68, 63.2%). Lastly, the glenoid track was assessed by 27 of 113 studies (23.9%), again most commonly with 3D CT (13 studies) and plain CT (seven studies). The assessment of glenoid and humeral bone loss is essential to treatment decisions for patient with recurrent anterior shoulder instability. Glenoid bone loss is most commonly assessed using cross-sectional imaging, most often 3D CT, and some variation of a best-fit circle applied to the inferior portion of the glenoid. Hill-Sachs lesion assessment was also commonly done using three-dimensional imaging; however, there was more variability in assessment methods across studies and there is an obvious need to unify the approach to humeral bone loss assessment for the purposes of improving treatment decisions and to better assess on-track and off-track lesions.

Does native glenoid anatomy predispose to shoulder instability? An MRI analysis

BACKGROUND

It is unclear if native glenohumeral anatomic features predispose young patients to instability and if such anatomic risk factors differ between males and females. The purpose of this study was to compare glenoid and humeral head dimensions between patients with a documented instability event without bone loss to matched controls and to evaluate for sex-based differences across measurements. The authors hypothesized that a smaller glenoid width and glenoid surface area would be significant risk factors for instability, whereas humeral head width would not.

METHODS

A prospectively maintained database was queried for patients aged <21 years who underwent magnetic resonance imaging (MRI) for shoulder instability. Patients with prior shoulder surgery, bony Bankart, or glenoid or humeral bone loss were excluded. Patients were matched by sex and age to control patients who had no history of shoulder instability. Two blinded independent raters measured glenoid height, glenoid width, and humeral head width on sagittal MRI. Glenoid surface area, glenoid index (ratio of glenoid height to width), and glenohumeral mismatch ratio (ratio of humeral head width to glenoid width) were calculated.

RESULTS

A total of 107 instability patients and 107 controls were included (150 males and 64 females). Among the entire cohort, there were no differences in glenoid height, glenoid width, glenoid surface area, humeral head width, or glenoid index between patients with instability and controls. Overall, those with instability had a greater glenohumeral mismatch ratio (P = .029) compared with controls. When stratified by sex, female controls and instability patients showed no differences in any of the glenoid or humerus dimensions. However, males with instability had a smaller glenoid width by 3.5% (P = .017), smaller glenoid surface area by 5.2% (P = .015), and a greater glenohumeral mismatch ratio (P = .027) compared with controls.

CONCLUSION

Compared with controls, males with instability were found to have smaller glenoid width and surface area, and a glenoid width that was proportionally smaller relative to humeral width. In contrast, bony glenohumeral morphology did not appear to be a significant risk factor for instability among females. These sex-based differences suggest that anatomic factors may influence risk of instability for male and female patients differently.

Editorial Commentary: A Consensus of Experts Complements the Clinical Evidence on Diagnosis and Treatment of Anterior Glenohumeral Instability

The current diagnostic and treatment strategies for anterior glenohumeral instability have been refined by high-quality clinical and basic science studies, but many controversies remain. These include the bone loss threshold for arthroscopic Bankart repair and the influence of other clinical factors on this decision, the optimal bracing position following anterior glenohumeral dislocation, and the optimal coracoid graft orientation during the Latarjet procedure. Randomized clinical trials often present conflicting results, and many of these are small-sample and fragile studies. Obtaining an expert consensus on the topic, by means of the Delphi method, is an attractive alternative to such clinical trials. Several studies employing variations of the Delphi method have addressed the diagnosis and treatment of anterior glenohumeral instability. These have stressed the importance of a meticulous technique during arthroscopic Bankart repair and of recognition of glenoid and humeral bone loss and treating this appropriately. These studies have also helped identify areas where consensus is modest or lacking to motivate additional clinical research study.

Editorial Commentary: Delphi Expert Consensus Clarifies Evidence-Based Medicine for Shoulder Instability and Bone Loss

Anterior glenohumeral instability with glenoid bone loss is a difficult problem and often requires open procedures with bone block augmentation. The current evidence suggests glenoid bone loss of 20% or more as a cutoff value indicating augmentation. Expert consensus-based techniques, such as the Delphi, clarify evidence-based medicine and allow pooling of expert opinion in a scientific fashion. These methods suggest that 3-dimensional computed tomography should be used to evaluate bone loss, previous dislocations, or failed soft-tissue surgery; Hill-Sachs lesions are poorly quantified by standard imaging; and, in cases with a bone deficit of >20%, glenoid bone graft should be considered. No consensus was reached regarding glenoid track evaluation, magnetic resonance imaging for evaluation of bone loss, safety of arthroscopic Latarjet, remplissage use for Hill-Sachs lesions of less than 30%, indications for a shoulder sling for 4 to 6 weeks after surgery, or postoperative rehabilitation timing and range-of-motion protocols.